Optical system, insulating glazing comprising such an optical system, process for manufacturing this insulating glazing and process for protecting an optical system

Abstract

An system includes an optical element including a glazing-function substrate and an electrochromic stack formed on this substrate, this electrochromic stack including a first transparent conductive layer, a working electrode arranged above the first transparent conductive layer, a counter-electrode arranged above said working electrode, a second transparent conductive layer arranged above the counter-electrode, lithium ions introduced into the electrochromic stack, and optionally a separate layer of an ionic conductor, the latter layer being intermediate between the electrode and the counter-electrode, a protective layer arranged on the electrochromic stack, the protective layer including an inorganic lubricating compound.

1 . An optical system comprising:
 an optical element comprising a glazing-function substrate and an electrochromic stack formed on the optical substrate, the electrochromic stack including a first transparent conductive layer, a working electrode arranged above said first transparent conductive layer, a counter-electrode arranged above said working electrode, a second transparent conductive layer arranged above said counter-electrode, lithium ions introduced into said electrochromic stack, and, optionally, a separate layer of an ionic conductor, the separate layer being intermediate between the electrode and the counter-electrode, and   a protective layer arranged on said electrochromic stack, said protective layer comprising an inorganic lubricating compound, and having a thickness comprised between 1 and 30 nanometers.   
     
     
         2 . The optical system as claimed in  claim 1 , wherein the inorganic lubricating compound comprises at least one of the following compounds: titanium oxide TiOx, tin-zinc oxide SnZnOx, titanium-strontium oxide TiSrOx, titanium-zirconium oxynitride TiZrOxNy, zirconium oxide ZrOx. 
     
     
         3 . The optical system as claimed in  claim 1 , wherein a difference in light transmittance between the optical element and an assembly comprising the optical element and said protective layer is smaller than or equal to 5% of a transmittance of the optical element. 
     
     
         4 . The optical system as claimed in  claim 1 , wherein the protective layer is arranged on said electrochromic stack so as to withstand all subsequent processing steps carried out on the optical system. 
     
     
         5 . The optical system as claimed in  claim 1 , wherein an assembly comprising the optical element and the protective layer has a coefficient of friction that is low with respect to a coefficient of friction of the optical element without its protective layer, each coefficient of friction being determined via a standardized tribometer measurement. 
     
     
         6 . The optical system as claimed in  claim 1 , wherein an assembly comprising the optical element and the protective layer has a coefficient of friction that decreases more rapidly than a coefficient of friction of the optical element without its protective layer following organic contamination, each coefficient of friction being determined via a standardized tribometer measurement. 
     
     
         7 . The optical system as claimed in  claim 1 , wherein an assembly comprising the optical element and the protective layer has a coefficient of friction that reaches a value lower than 0.5 in a time comprised between 1 and 100 hours. 
     
     
         8 . The optical system as claimed in  claim 1 , wherein said substrate is tempered. 
     
     
         9 . The optical system as claimed in  claim 1 , further comprising an additional protective layer comprising an organic compound that covers said protective layer. 
     
     
         10 . The optical system as claimed in  claim 9 , wherein said organic compound comprises carbon. 
     
     
         11 . The optical system as claimed in  claim 9 , wherein the additional protective layer has a thickness comprised between 1 and 10 nanometers. 
     
     
         12 . The optical system as claimed in  claim 9 , wherein the additional protective layer is removable with a heat treatment at a temperature comprised between 300 and 500° C. 
     
     
         13 . The optical system as claimed in  claim 1 , wherein:
 said working electrode is made from an electrochromic material based on tungsten oxide WOx or lithium-tungsten oxide LiWOx and said counter-electrode is made of an oxide of a tungsten-nickel alloy,   the layer of ionic conductor comprises a layer of silicon oxide SiOx,   said first and second transparent conductive layers are made based on indium-tin oxide (ITO).   
     
     
         14 . The optical system as claimed in  claim 13 , furthermore comprising, between said substrate and the first transparent conductive layer, an under-layer comprising an alternation of at least one layer based on niobium oxide and of at least one layer based on silicon oxide. 
     
     
         15 . The optical system as claimed in  claim 13 , further comprising an over-layer arranged on the second transparent conductive layer comprising a layer based on silicon oxide. 
     
     
         16 . An insulating glazing comprising, assembled together, an optical system as claimed in  claim 1 , a spacer and another glazing-function substrate. 
     
     
         17 . A process for manufacturing an insulating glazing comprising an optical system as claimed in  claim 1 , said process comprising:
 forming the electrochromic stack on said glazing-function substrate,   arranging the protective layer on said electrochromic stack,   handling and/or converting and/or processing and/or transporting and/or washing and/or storing the optical system,   optionally assembling, via lamination of a face of the glazing-function substrate which is opposite a face located on a side of the electrochromic stack, with a counter-substrate,   assembling said optionally laminated optical system with a spacer and a second glazing-function substrate to form the insulating glazing.   
     
     
         18 . The process for manufacturing an insulating glazing as claimed in  claim 17 , comprising:
 cleaving or cutting the glazing-function substrate,   tempering the glazing-function substrate after the forming of the electrochromic stack.   
     
     
         19 . A process for protecting an optical element comprising a glazing-function substrate and an electrochromic stack formed on the substrate, the electrochromic stack including a first transparent conductive layer, a working electrode arranged above said first transparent conductive layer, a counter-electrode arranged above said working electrode, a second transparent conductive layer arranged above said counter-electrode, lithium ions introduced into said electrochromic stack, and, optionally, a separate layer of an ionic conductor, the separate layer being intermediate between the electrode and the counter-electrode, the method comprising arranging a protective layer on said electrochromic stack, said protective layer comprising an inorganic lubricating compound, and having a thickness comprised between 1 and 30 nanometers. 
     
     
         20 . The process as claimed in  claim 19 , further comprising arranging an additional protective layer that covers said protective layer, the additional protective layer comprising an organic compound, and subsequently removing the additional protective layer with a heat treatment at a temperature comprised between 300 and 500° C.